[Enamel and dentin under the ultrasonic microscope].

Ultrasonic reflection scanning microscopy is a new method for imaging the known structures of dental hard tissues on the basis of a simple specimen preparation. The specimens are scanned in a physiologic humid environment. Particularly high-contrast images are obtained from enamel tufts and lamellae, dentin tubules and interglobular dentin.

A new method for the simultaneous presentation of low and high magnifications of microscopic specimens: application to in vivo studies of mesenterial capillaries.

By combining an incident light microscope (C. Zeiss) with an inverted camera microscope (ICM 405, C. Zeiss) having a common optic axis, it was possible to present simultaneously two microscope images of one object.

Myoglobin-O2-saturation profiles in muscle sections of chicken gizzard and the facilitated O2-transport by Mb+.

It has been shown that the oxygen transport in intact muscle can be quantitatively determined using Mb as an oxygen indicator in the cryomicrophotometric method. 1) The influence of the parameters such as time, temperature, boundary PO2 and metabolism on the oxygen transport in sections of chicken gizzard could be quantitatively determined from measured MbsO2-profiles; 2) The MbsO2-profiles measured under various conditions can be reproduced using a mathematical model which considers not only the diffusion of dissolved O2 but also the facilitated diffusion as well as O2 consumption. From this mathematical results it can be concluded that the mobility of the Mb in the muscle cells is limited and that Mb in the PO2-region between 5 and 0 mmHg contributes to at most 40% to the total O2-transport in chicken gizzard.